Local Warming

Sarah Day | Mar 01, 2007

If you want to save money on heating, you might consider an alternative source to conventional heating. Natural gas and propane-fired infrared heaters can save up to 50% on fuel consumption and are a cleaner, safer heat source, according to infrared heater manufacturers. These heaters are more efficient because they radiate heat to the floor rather than circulating the warmed air around the ceiling like conventional forced air systems do.

“As farmers are moving away from drafty, old buildings and replacing them with more insulated metal ones, they want better control over the way they heat their space,” says Bill Shields, president of Heatronics, Des Moines, IA. He claims that infrared heaters are the most economical choice for fuel savings and heat efficiency.

How they work

Infrared heat does not produce air movement, says Tom Lester, vice president of sales and marketing for Solaronics, Rochester, MI. “When infrared energy strikes an absorptive object such as a concrete floor or a person, it is converted into heat at the surface,” he explains. The surrounding air is then warmed by transferring heat from the objects in the room.

A burner box is located on one end of the radiating tubes that contain the combustion chamber where the air and gas are mixed. The other end is where the exhaust is located, dispelling the combustion by-products. A fan pushes the heat down the tube where bright aluminum reflectors direct the heat rays onto the ground. All objects in the room absorb the infrared rays and become warm.

Infrared heaters work well in agricultural buildings. “A forced air unit heats up the air in the space, and once a door opens much of the heat escapes to the outside, taking more time to reheat the space,” reports Michelle Fox, product support assistant of Detroit Radiant, Warren, MI. “Since an infrared heater heats up objects and people, the floor acts like a heat sink and stores that heat. Once the doors close, the space will see a much more rapid heat recovery.”

These heaters come in two forms: single-stage and two-stage burners. The single-stage burner has been around since the 1950s. In 1990, manufacturers introduced the two-stage burner. Single-stage heaters can be used in both high and low ceiling areas, Shields explains. These heaters help maintain a constant temperature in the building.

Compared to two-stage heaters, one-stage heaters sometimes require more heaters, depending on ceiling height, than two-stage burners do. The single-stage heaters operate on one setting, and after reaching it, they turn off. Because they feature only a high setting, they create both too much and not enough heat at inopportune times, Fox says.

Most farm shops have 12- to 16-ft. ceilings. Dual-stage burners are ideal for these buildings because they increase comfort and conserve fuel, Shields says. These heaters are also ideal in situations with extreme cold. The heaters use gas staging, which fire on a high stage to get the temperature up and then operate on the low stage about 80% of the time. This creates a more comfortable heat environment without hot or cold temperature extremes.

“The two-stage heaters are the most economical to run and are the most efficient,” Lester says. “They have the best combustion at both stages and there is no wasted fuel.”

These heaters use less radiant heat and fuel input, saving a minimum of 12% more fuel over a single-stage burner. The two-stage burners cost $100 to $120 more than the single-stage burners, but manufacturers say the money usually can be paid back in fuel savings in less than one heating season.

More advantages

There are other advantages to low-intensity infrared heating systems. The heaters can be vented to the outdoors and use the outside air for combustion, which prevents the buildup of water and CO2. With mounting heights at as little as 8 ft., infrared heaters can heat objects in a short time.

Another advantage is spot heating. “In farm shops, most people want to heat the whole shop, but they want to do so more efficiently,” Shields says. “With infrared we can direct the heat and keep it warm without as much transfer as you would get with a forced air system.” Infrared heat allows farmers to “zone” or direct the heat to a particular area and not waste fuel on heating unused areas.

According to Fox, infrared heaters are a cleaner, safer heater source because they have no moving parts to blow dust and debris. The initial setup costs will be greater than those of the forced air system, but manufacturers say you should expect to cover your costs in less than one heating season.

Constant temperature

Solaronics' two-stage heating systems feature a newly patented True Dual Two-Stage Infra-Red Heater. “Unlike other systems claiming to stage operation, both the air and gas combine in the exact ratio at both the high- and low-heat stages so you get the best combustion without wasting fuel,” Lester says. This means the heater will operate in high-heat mode when the facility is cold to quickly set the desired temperature. Once the set temperature is reached as determined by the two-stage thermostat that you set, it will operate on the lowest burner setting, maintaining a constant temperature.

The heater runs on a standard 120v power and features easy installation with a simple chain mount.

More even heat

Detroit Radiant's HL2 is a patented two-stage heater that runs on natural or propane gas. While most heaters feature a burner that produces a short, straight flame, the HL2 features a stainless steel swirl burner that pushes the flame further down the tube for the maximum amount of output. A highly polished aluminum reflector located over the tube directs the heat rays down. A tube with a coated black finish helps direct the heat from the tube down to the floor for more even heat throughout the building.

The heaters come in lengths of 20 to 80 ft. They run on a standard 120v.